1. Field of the Invention
The present invention relates generally to a joint structure of a handrail, and more particularly to an innovative handrail with a coupling tube at the joint.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
The existing handrail is assembled and fixed onto the wall via its joint. Since the external diameter of the joint is much bigger than the handrail, the joint is individually fabricated and then combined with the handrail. For this reason, the present invention is intended to improve this coupling joint of the handrail.
The disadvantages of typical prior art structures are detailed in the first prior art structure as shown in FIG. 1, wherein the joint 11 and handrail 12 are soldered with soldering flux 13. However, it is found from the applications that, uneven bead and local shelling of soldering flux likely occur during the soldering process, leading to lower yield and higher cost as well as a time-consuming manufacturing process.
Another disadvantage is shown in the second prior art structure shown in FIG. 2, wherein the joint 21 and handrail 22 are fastened securely by means of screwing. In other words, a screw section 23 is placed at the end of the handrail 22, and a bolt hole 24 set at the center of the joint 21. So, the screw section 23 is screwed into the bolt hole 24 for fastening of the joint 21 and handrail 22. However, it is found that the handrail 22 is made from a pipe with a wall depth only about 1-1.5 mm. So, the thinner screw section 23 will offer an excessively small bonding force of the joint 21 and handrail 22, leading to poorer strength and degraded durability in the application.
Still another disadvantage is shown in the third prior art structure shown in FIG. 3, wherein the joint 31 and handrail 32 are fastened by pin connection. The joint 31 is die-cast from aluminum zinc alloys, and a protruding tube 33 is set at the center of joint 31 for mating with the end 34 of the handrail 32. Two radial through-holes 35, 36 are placed in opposition on the protruding tube 33 and end 34 of the handrail 32, allowing insertion of a pin 37 for a positioning purpose. However, it is found that the handrail 32 is commonly used in a bathroom or toilet, where it is exposed to moisture or cleaning agents with acid corrosion. In such a case, the joint 31 die-cast by aluminum zinc alloys likely generates oxidation and corrosion, leading to loss of structural strength and lower service life. The protruding tube 33 of joint 31 must be thick enough (approx. 3 mm) to support securely the pin. Given the fact that die-cast protruding tube 33 has a solid wall, this design is not perfectly suitable for mass production due to much higher costs, which are disfavored manufacturers.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve efficacy.
To this end, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.